Artificial limb



April 19, 1-955 H. sARTlN er1-AL 2,706,297

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ARTIFICIAL LIMB 2 Sheets-Sheet 2 Filed Feb. 26, 1954 i m ,N WMM .M mw@ w IEE T D A s., Y M m L .am www A l H m M O m pivots for movement over United States Patent O ARTIFICIAL Luw Hansel Sartin and Ruth M. Dean, Long Beach, Calif.

Application February 26, 1954, serial No. 412,198

This invention relates to an artificial limb and has for its primary object to simulate both in shape and action a natural limb.

Another object is to facilitate the mounting of a knee joint between a stump socket and calf portion and to ensure smooth operation of the knee joint.

A further object is to cushion the shock normally transmitted from the foot of an articial limb to the stump socket thereof and thus to contribute to the comfort of the user.

Still another object is to control the return of the knee joint to vertical position after its having been bent.

The above and other objects may be attained by employing this invention which embodies among its features a hollow head having a convex toric surface simulating a knee cap, connecting means carried by the head and extending upwardly therefrom adjacent one end of the toric surface for connection to the stump socket of an artificial limb, a back wall carried by the head adjacent the opposite end of the toric surface and lying substantially perpendicularly to the connecting means, aligned pivots carried by the head and lying along an axis which extends transversely through the head, a yoke mounted on the the convex toric surface in spanning relation therewith, attaching means carried by the yoke and extending outwardly therefom in substanytially perpendicular relation to the transverse axis for connection to the calf portion of the limb, and means carried by the yoke and operatively connected to the head for yieldingly holding the connecting means and the attaching means in substantial longitudinal alignment.

Other features include antifriction bearings carried by the head and lying along the axis which extends transversely through the head, pivots carried by the antifriction bearings, and a yoke mounted on the pivots for movement about the axis over and in spanning relation to the toric surface.

Still other features include aligned tubular cushions in which the antifriction bearings are mounted, a stop carried by the yoke, and a stop pad carried by the head for engagment by the stop when the connecting means and the attaching means lie in substantial alignment.

In the drawings:

Figure 1 is a vertical sectional view through an artificial limb embodying the features of this invention and showing the limb in its upright position;

Figure 2 is a vertical sectional view taken substantially on the line 2-2 of Figure 1;

Figure 3 is a fragmentary enlarged sectional view taken substantially on the line 3--3 of Figure l;

Figure 4 is a fragmentary enlarged sectional view taken substantially on the line 4-4 of Figure 1;

Figure 5 is a view similar to Figure l, showing the limb in action with the knee and toe bent; and

Figure 6 is a fragmentary sectional view showing the artificial foot rocked backward on the heel portion thereof with the toe elevated.

Referring to the drawings in detail, the knee joint designated generally 10 for the artificial limb comprises a head 12 having a convex toric surface 14. A back wall 16 is carried by the head adjacent one end of the convex toric surface 14 and carried by the head and extending inwardly thereof adjacent the opposite end of the toric surface is an inwardly extending flange 18 carrying at its inner edge an upwardly extending ange 20 which anges cooperate in defining a shoulder 22 upon which the lower end of a conventional stump socket 24 is seated.

ICS

The ange 20 is provided at spaced intervals with internally screw threaded openings for the reception of attaching screws 26 by means of which the stump socket is rigidly secured to the knee joint 10. Entering opposite sides of the head 12 in axial alignment with an axis which extends transversely through the head and about which the convex toric surface 14 lies in spaced concentric relation are openings 28 surrounded by inwardly extending anges 30 which form seats for ring-shaped cushions 32 in which are seated the antifriction bearings, to be more fully hereinafter described.

Seated in the ring-shaped cushions 32 are the outer races 34 of antifriction bearings designated generally 36, the inner races 38 of which are supported for rolling contact on cylindrical rollers 40 of the type commonly employed in needle bearings. Extending between the adjacent ends of the antifriction bearings 36 is an internally screw-threaded tubular body 42 which engages the adjacent ends of the antifriction bearings 36 to prevent longitudinal displacement of said bearings inwardly with relation to the knee joint 10. Pivot pins 44 extend through the inner races 38 of the antifriction bearings and are provided with externally screw-threaded extensions 46 which are adapted to threadedly engage the internal threads of the sleeve 42. Carried by the tubular body 42 adjacent opposite ends thereof are spacing rings 48 which engage the antifriction bearings 36 and define midway between opposite ends of the tubular body 42 an annular groove in which a roller 50 is rotatably supported on the tubular body 42.

Mounted on the pivot pins 44 for movement about the transverse axis are the arms 52 of a yoke designated generally 54 which spans the convex toric surface 14 of the head 12 and moves in an arcuate path about said head. Carried by the yoke is an inwardly extending flange 56 carrying at its inner edge an outwardly extending collar 58 which defines with the ange 56 a seat 60 against which the upper end of the calf portion 62 of the artificial limb abuts. The collar 58 is provided at spaced intervals with internally screw-threaded openings for the reception of attaching screws 64 which extend through the calf portion 62 to secure said calf portion to the knee joint 10. A bridge 66 extends transversely through the collar 58 for supporting the leg retractile element, to be more fully hereinafter described. Extending through the back Wall 16 of the head 12 and into the convex toric surface thereof is a slot 68 and carried by the head at the end of the slot which is located within the convex toric surface is a buffer 70. A stop 72 is carried by the bridge 66 and projects into the slot 68 for engagement with the buffer 70 when the socket member 24 and calf portion 62 are in substantial vertical alignment. The stop 72 is grooved as at 74 and extending through the bridge 66 in alignment with the groove 74 is an opening 76 through which a guide pin 78 is mounted to slide. As illustrated in the drawings, the guide pin 78 extends downwardly below the bridge 66 and into the calf portion 62 of the artificial limb and is surrounded by a compression coil spring 80, the tension of which is adjusted by a nut 82 which is threadedly engaged with the rod 78. Connected to the rod 78 adjacent the end thereof which is disposed within the guide groove 74 is a cable 84 which extends around the roller 50 on the tubular body 42 and carries adjacent the end thereof remote from the guide pin 78 an externally screw-threaded stud 86 which extends upwardly through an opening formed in a transversely extending arch 88 carried by the collar 20, and threadedy engaged with the stud 86 is a nut 90 which bears on the arch 88 to adjustably regulate the tension of the cable 84.

A foot designated generally 92 comprises an instep and heel portion 94 to the forward end of which is pivotally coupled for movement in a vertical arcuate path a toe portion 96. Carried by and extending transversely across the instep and heel portion 94 adjacent the upper end thereof is a pivot pin 98 upon which is mounted intermediate its ends an antifriction bearing 100 carrying a substantially U-shaped yoke 102, the legs 104 of which project upwardly in substantially spaced parallel relation and are provided with longitudinally spaced internally screw-threaded openings for the reception of fastening screws 106 by which the lower end of the calf portion 62 of the artificial limb is coupled to the foot 92. Carried by and extending between the legs 104 of the U-shaped yoke 102 ris a block 108 having openings 110 and 112 extending therethrough adjacent the forward and rear ends thereof, respectively. Mounted for longitudinal sliding movement in the opening 110 of the block 108 is a guide pin 114 to the lower end of which is connected a suitable cable 116 which is anchored as at 118 in the instep and heel portion of the foot on the side of the pivot pin 98 toward the toe portion 96. A similar guide pin 120 is mounted for longitudinal sliding movement in the opening 112 and coupled to the lower end of the guide pin 120 is a cable 122 which extends downwardly through an opening 124 in the instep and heel portion of the artificial foot and is trained over a pulley 126 mounted in the instep and heel portion 94 adjacent the rear end thereof. The cable 122 is carried forwardly through a passage 128 in the instep and heel portion 94 of the foot 92 and is anchored at a 130 in the toe portion 96 thereof. Resting on the upper side of the block 108 and extending upwardly therefrom in surrounding relation to the guide rod 114 is a compression coil spring 132, the upper end of which is operatively engaged by a nut 134 which is threadedly engaged with the rod 114 adjacent the upper end thereof so that the cable 116 may be tensioned to a selected degree. A Simiar compression coil spring 136 is seated on the block 108 in surrounding relation with the guide pin 120 and the tension of the cable 122 is governed by a nut 138 which threadedly engages the rod 120 adjacent the upper end thereof and operatively bears on the upper end of the spring 136. It will thus be seen that by adjusting the nut 138, the tension of the cable 122 may be adjusted.

In use, it will be evident that the tension on the cables 116 and 122 may be regulated to attain a selected reaction between the toe portion 96 of the artificial foot 92 and the artificial calf 62 of the artificial limb. It will also be evident that by adjusting the nut 82 on the threaded end of the rod 78, the reaction of the calf portion 62 with the stump socket 24 may be regulated. Because of the fact that the antifriction bearings are ernployed in the knee joint, a smooth operation thereof will be ensured and moreover by reason of the fact that the antifriction bearings are surrounded by cushions 32, 4

shocks which are normally transmitted to the stump socket will be cushioned and consequently will not be transmitted to the person of the user. As a result of using the knee joint of the type herein described, it is obvious that the artificial limb may be adjusted to react in substantial conformity with the coordination of the user and will contribute materially to concealing the -fact that an artificial limb is in use.

While in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be restorted to without departing from the spirit and scope of the invention as claimed.

What is claimed is:

A knee joint for an artificial limb comprising a hollow head having a convex toric surface simulating a knee cap, connecting means carried by the head and extending upwardly therefrom adjacent one end of the toric surface for connection to the stump socket of an artificial limb, a back wall carried by the head adjacent the opposite end of the toric surface and lying substantially perpendicularly to the connecting means, aligned tubular cushions seated in and extending through opposite sides of the head in axial alignment with a common axis which lies parallel to the back wall, antifriction bearings extending through the cushions and lying along the common axis, pivots mounted in the antifriction bearings for rotary movement about the common axis, a yoke carried by the pivots and spanning the convex toric surface for movement thereover about the common axis, said head having a slot extending through its back wall and the convex toric surface adjacent the junction of the back wall with the toric surface, a bridge carried by the yoke and extending transversely thereacoss in perpendicular relation to the common axis, a stop carried by the bridge and extending into the slot for movement with the yoke in an arcuate path, a stop cushion carried by the head and extending into the path of movement of the stop for arresting movement of the yoke about the head in one direction, and means carried by the bridge and operatively connected to the head for yieldingly urging the stop against the stop cushion and the connecting means and the attaching means in substantial axial alignment.

References Cited in the file of this patent UNITED STATES PATENTS 772,753 Staggs Oct. 18, 1904 2,483,506 Sartin Oct. 4, 1949 2,529,968 Sartin L Nov. 14, 1950 2,629,105 Woodall Feb. 24, 1953 

